Saitama and Genos begin to rise in the ranks at the Hero Association and it's really great to see their dynamic grow.  Saitama will spout these one liners that are rather profound in such a deadpan and obvious way that have me pause to consider how I value things in life.

The main downside to this series that I've noticed thus far is the character Puri Puri Prisoner.  He's a gay "hero" but he has assaulted men in the past and so he's actually more of a villain because all he cares about is protecting his boys so he can assault them later.  It seems so needless to have his main characteristic be his sexuality.  I think the idea of a hero that goes to prison for breaking the law is actually a compelling thing, but for it to be the one obviously gay character...  It's a shame to vilify that.

While I really enjoy most of One-Punch Man, the one thing that really bothers me is the homophobia, which shows up here for the first time. While relatively typical of manga/anime, I still really don't like it!

Other people have described the problems with Puri-Puri Prisoner better than I could, but basically, it's extremely homophobic, and it's even worse in the manga than the anime due to the extra bonus chapter in this volume. Some people may try to argue that since One-Punch Man is a satire, this is a satire of the depictions of gay people in manga, but given the lack of other gay characters, I think it's pretty clear that this is just homophobic.

So this one gets two stars, but I knew this was present going into this so I was prepared for it.